x, y, p, q = map(float, input().split())
ans = ((p-x)**2 + (q-y)**2)**0.5
print(f"{ans:.8f}") x, y, p, q = map(float, input().split()) x map(float, input().split()) map float input().split() ().split () input split y p q ans = ((p-x)**2 + (q-y)**2)**0.5 ans ((p-x)**2 + (q-y)**2)**0.5 (p-x)**2 + (q-y)**2 (p-x)**2 p-x p x 2 (q-y)**2 q-y q y 2 0.5 print(f"{ans:.8f}") print f"{ans:.8f}" x, y, p, q = map(float, input().split()) map(float, input().split()) x p, q = map(float, input().split()) map(float, input().split()) p ans = ((p-x)**2 + (q-y)**2)**0.5 ((p-x)**2 + (q-y)**2)**0.5 ans y, p, q = map(float, input().split()) map(float, input().split()) y q = map(float, input().split()) map(float, input().split()) q
x, y, p, q = map(float, input().split())
ans = ((p-x)**2 + (q-y)**2)**0.5
print(f"{ans:.8f}")
